In chemical and biological laboratories, sample transfer from a source plate to a target plate (or piece of lab ware) is a fundamental task. Typically a pipette or pipetter system is used to (i) collect a desired sample from the source piece of lab ware which holds the sample in one array format, and (ii) deliver/dispense the collected sample to the target piece of lab ware in the same or another array format. Current pipetter systems generally use pistons with seals to move a volume of air in and out of the piston cylinder. The air is used as the working fluid to draw the sample in or out of the pipetter (piston cylinder). Models of various systems are available with multiple pistons (up to 12 pistons, such as the Finnpipette from Labsystems, Inc.) which are aligned in a row at standard 9 mm spacing for filling single rows of microtitration plates. The various pipetter systems are available in models which are manually actuated with a thumb pushbutton, or automatically actuated with a motor.
Another piperting device (such as the one designed by Robbins Scientific, Inc.) uses several Hamilton syringes positioned together in a holder. The Hamilton syringes are extremely precise glass syringe systems with an elastomer air tight seal, and a thin hypo-tube tip. An array of these syringes requires large actuation forces because of the friction in the seals, and the array density is limited by the width of the glass syringes. The cost of each such syringe is also high due to the precise machining of the glass.
In addition preexisting piperting systems used for small volume samples (less than about 10 .mu.l) have a disadvantage in dispensing collected samples. In order to dispense a collected sample, the sample must be touched to a portion of a target plate in order to release the sample from the pipette.
Accordingly, improvements are needed in pipetter systems. And in particular, improvement is needed in such pipette systems used for transferring several samples in an array format from one piece of lab ware to another in a potentially different array format.